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Thread: LLY Reading question

  1. #1
    Tuner in Training
    Join Date
    Apr 2015
    Posts
    33

    LLY Reading question

    I am unable to read my LLY at high speed no matter what fuses I pull. Both batteries are fully charged, my laptop is fully charged, the winds blowing the right way, it's not a full moon, yada, yada, yada. I can however read it in slow speed, but I cannot read the ECM & TCM in the same read. I can read the TCM separately however. All good right? Not quite, My ECM reads that i have 3.73 gearing while me TCM shows 4.10. Is this normal? Has anyone else seen this? Is my read corrupt? I'm attaching my reads in hope of some assistance. New to diesel but have plenty of experience with gas motors. Thanks in advance.

    Initial ECM Read.hpt
    Initial TCM Read.hpt

  2. #2
    Tuner in Training
    Join Date
    Apr 2015
    Posts
    33
    Wow! The LLY really is a dead subject with Hptuners! I guess the rumor is correct that the competitor is the only way to go with diesel......

  3. #3
    Did you enter a ticket with HPT?

    I haven't experienced what you are but...i do know my LB7 was clunky when read/writing. And yes the competitor focused more on those diesels over those years, where HPT went more gas. They each have their place.
    2006 GTO 403ci lsa heads kooks long tubes corsa ss exhaust OTR intake HPTuned

    2010 GMC Sierra LMM Duramax. Exhaust and tuned

  4. #4
    Potential Tuner
    Join Date
    Mar 2021
    Posts
    1
    I can read LLY by itself with high speed but must read TCM slow speed and it?ll do it all in one shot. Can read TCM alone with high speed. As far as the two seperate gear ratios mine does exact same thing. An from trial an error I?ve learned to leave the top one at 3.73 and only adjust the bottom one to allow for tire size change. Another odd thing when looking at TCM read it shows I have a 6 speed and I don?t. Not sure why it?s so goofy. I?d probably had gone with the competition?s hardware if I was to do it all over again just to use their software.

  5. #5
    Potential Tuner
    Join Date
    May 2023
    Location
    South Mississippi
    Posts
    9
    if you have an aftermarket radio with the converter i.e., if it had premium sound of sorts and has the middleman converter to turn the radio on, the converter box talks to the can signal to enable power to the aftermarket radio. your issues may lie there. if you have the setup as I described simplest is to unplug the converter and read again, all of this depending on if this applies to you.

  6. #6
    Potential Tuner EXPO0187's Avatar
    Join Date
    Dec 2022
    Location
    North Ga
    Posts
    6
    Make sure you pull the radio and amplifier fuse under the hood then it will read this is a normal issue with older Duramax trucks.

  7. #7
    This is normal. Even using other software you will get the same thing on the AL5.

  8. #8
    Advanced Tuner JaegerWrenching's Avatar
    Join Date
    Jun 2018
    Location
    Albuquerque New Mexico
    Posts
    465
    I just recently had an 04 LLY That wouldn't let me read it on high speed with the under hood fuse #50 still installed. It did however let me read both ECM/TCM on low with that fuse installed. Truck has an aftermarket radio just FYI. So I flashed just the ECM about 4 times and both ECM TCM 3 times on low without any issues. Sent the customer on his way. Some mods/changes and about a year later we flashed ECM only again on low speed another 6 times no problem. After some smoothing of the pedal map to my customers liking and trying to flash it again on low, it failed a write mid flash. After that it wouldn't write more than 0-0.4% and time out every time. I tried to write entire and it got to writing and then failed at the same spot. I removed both negative battery terminals and found the passenger side battery to have some corrosion between the terminal and battery but nothing crazy. Cleaned it and reseated both terminals, then pulled fuse #50 and it hit write calibration instead of entire on accident but on high speed and it went all the way through to the end where it had failed. But since I'd already erased entire that is why it failed at the very end. So I tried to write entire on high speed and it failed on the erase part... Then in the midst of all this I somehow forgot to go key on and I hit write entire on low speed and it wrote all the way through for the full 15+ minutes and only realized what i'd done when I went to turn the key off... but I went key on and it fired right up. Made one more set of changes, flashed high speed key on calibration only with fuse 50 still removed and it worked first try. Truck left running great! I still don't understand how it flashed and took with the key in the off position.... it was a solid 15 maybe even 20 minute to write entire on regular speed.... All I know is I said a prayer before that final attempt to write and God always delivers...